Manufacture of imidazolines



Patented Sept. 24, 1940 PATENT OFFICE 2,215,863 MANUFACTURE OFIMIDAZOLINES Edmund Waldmann, Klosterneuburg, and August Chwala, Vienna,Germany, assignors, by mesne assignments, to General Aniline & FilmCorporation, New York, N. Y., a corporation of Delaware No Drawing.Application March 22, 1939, Serial No. 263,395. In Austria April 4, 1936This application is a continuation-in-part of application Serial No.94,120, filed August 3, 1936.

This invention relates to the manufacture of imidazolines containingaliphatic radicals of high molecular weight as substituents at the 2-carbon atom by heating with a fatty acid or a carboxylic acid of highmolecular weight to high temperatures, preferably to temperatures lyingbetween 200 and 300 0., a mixture consisting on the one hand of a basehaving a primary amino-group and a second primary or secondaryamino-group, which are in 1:2-position to each other, the two carbonatoms in lz2-position being linked by a single bond, and on the otherhand a salt of such base formed from a strong acid.

Suitable bases having a primary aminogroup and a second primary orsecondary aminogroup in 1:2-position to each other are ethyl enediamine;products such as diethylenetriamine, triethylenetetramine,tetraethylenepentamine; homologues of ethylenediamine such as1:2-propylenediamine, 2:3 butylenediamine, N- methylethylenediamine.

Suitable strong acids for forming the salts are amides, anhydrides orhalides; according to the selection of the derivatives to be used, thesimultaneous use of the free base or the salt of the base may, ifdesired, be omitted, for in the case of halides the suitable mixturesleading to the desired result are formed, due to the mineral acidbecoming free, in the course of the acylation.

Quite generally, the new process consists in heating with a productselected from the group consisting of fatty acids of high molecularweight and the salts, amides, halides and esters thereof, a mixtureconsisting on the one hand of a base which is substituted at two carbonatoms adjacent to each other by an amino-group each, of whichamino-groups one contains two hydrogen atoms and the other at least onehydrogen atom, and on the other hand of a salt of such base with astrong acid, the heating being carried out at a high temperature.

The procedure may also be such that first of all the salt of themono-acyl compound is prepared. The process then consists in heating toa high temperature a salt formed from a strong acid and such a diaminemono-acylated with a fatty acid of high molecular weight, in which thetwo amino groups are bound to two carbon atoms adjacent toeach other,one of which amino groups containing two hydrogen atoms and the other atleast one hydrogen atom.

In the preferred mode of operating, the mixture made in accordance withthe invention is heated to a temperature of 250-290 C. If, for example,there is used a quantity of lauric acid, ethylenediamine andethylenediamine-hydrochloride the hydrochloride which forms a sedimentdissolves very quickly in this interval of temperature, even with onlygentle stirring, and at the same time causes formation of theundecyl-imidazolinehydrochloride. This reaction may also be conducted ata temperature lower than 250 C. by heating for a longer period. The useof a vacuum during the second half of the condensation is useful.

When the condensation to the imiclazoline derivative starts from amixture of fatty acid amine and aminehydrochloride, the three componentsof the mixture are advantageously selected so that for 1 mole of thefatty acid or its derivative there are at least 1 mole of the diamineand the salt-like bound mineral acid. In using 1 mole of lauric acidtherefore, there should be mole ethylenediamine and mole ethylenediaminehydrochloride, corresponding with the and there is obtained thehydrochloride of un-.

decylimidazoline.

If as the lauric acid derivative there is chosen thedilauroylenethylenediamine which for one mole of lauric acid alreadycontains mole of ethylenediamine in a bound state, and 1 mole of thisdiacyl-body is heated with 1 mole of ethylenediamin-ehydrochloride atabout 250-290 C. there is obtained the reaction in the sense of thefollowing equation:

C11H2QCONHCQH4NHCOC11H23 NHaC2HiNHa2HCl NH-GH2 ZCIIHQBO V.HC1+2H3O N-OH2the product being again undecylimidazolinehydrochloride in approximatelyquantitative yield.

If, however, the parent material is themonolauroylenethylenedi-aminehydrochloride which already contains initself per 1 mole fatty acid 1 mole of ethylenediamine and 1 mole ofhydrochloric acid, it suffices to heat this hydrochloride by itself toabout 250-300 C. in order to obtain an excellent yield of thehydrochloride of undecylimidazoline. This reaction can also be carriedout with the other mono-acylderivatives which are obtained from thediamines and the fatty acids of high molecular weight mentioned inparagraphs 2 and 4 of this specification.

Under the effect of the amine salt, particularly the hydrochloride, onefinds at comparatively high temperature of reaction evidently anelimination of the acid amide at first formed (as may be seenparticularly clearly from the example of dilauroylethylenediamine) andthen a combination of .the eliminated material directly to theimidazoline hydrochloride. Philipps (Journal of the Chemical Society ofLondon, 1928, page 2393 and following; Chemisches Zentralblatt 1928,vol. 2, page 2466) is of opinion that the formation of benimidazoles orimidazolines from the acylderivatives of the corresponding diamines byboiling with hydrochloric acid occurs of itself in such a manner thatthe acid amide is first saponified and the eliminated portion uniteddirectly to the benzimidazol or imidazoline.

These imidazolines of high molecular weight in the form of their saltsare freely soluble in water; solutions foam and have good capillaryactive properties. They may be used with advantage for improving dyeingson vegetable fibers.

Sulfo-groups may be introduced in their molecules by the methods whichhave become known from French Specification No. 796,917. Theseimidazoline-sulfonates of high molecular weight are also valuable aswetting, foaming, Washing, emulsifying and dispersing agents. They arevaluable as assistants in the textile industry.

The following examples illlustrate the invention, the parts being byweight:

Example 1 Into a stirring vessel provided with a thermometer and aninverted condenser there are charged 284 parts of stearic acid, 93 partsof ethylenediaminehydrochloride, 56 parts of ethylenediaminehydrate. Themixture is heated while stirring to 120 C. and the temperature is raisedwithin 90 minutes to 185 C., whereby between 170 and 185 C. a smallproportion of a clear liquid distils (ethylenediaminehydrate and water).The mixture is now heated within 30 minutes to 230 C. and then within 15minutes to 290 C. The mass is kept for a short time at this temperature,which may be raised to 300 C. until a sample of the mass, tested withwater, shows that it is soluble in water to a clear solution; theheating is then interrupted and the mass cooled. The brownish mass,which is crystalline when cold, consists almost exclusively ofheptadecylimidazolinehydrochloride.

A free base may be separated in known manner by dissolving thehydrochloride with water and liberating the base with analkali-hydroxide which can then be directly filtered or extracted bymeans of benzene. For further purification the product may becrystallized from a mixture of 3 parts of methyl alcohol and 1 part ofwater, whereby 2-heptadecylimidazoline is obtained in crystalline scalesmelting at 94-95 C.

Example 2 In an apparatus such as is described in Example 1 there isheated a mixture of 130 parts of lauric acid, 40 parts ofethylenediaminehydrate, 60 parts of ethylenediaminehydrochloride inmanner described in the same example. As soon as a sample of the mass isclearly soluble in water, the heating is interrupted. On cooling, themass solidifies in crystalline form; it consists of 2-undecylimidazolinehydrochloride. The base liberated in the usual mannerfrom this salt may be purified by recrystallization from alcohol of 50per cent. strength, whereby it is obtained in the form of colorlesslaminae which melt at 82 C.

Example 3 In an apparatus such as is described in Example 1 there isheated to 180 C. a mixture of 140 parts of oleic acid, 15 parts ofethylenediaminehydrate; the mass which at first is somewhat foamy boilsfinally gently as soon as the water has been distilled. After cooling to120 C. there are added another 15 parts of ethylenediaminehydrate andheating is renewed to 180 C. 37.5 parts of ethylenediaminehydrochlorideare now added, whereupon the temperature of the mass is raised to 280 C.Within 15 minutes and kept there for 10 minutes. The mass is thenallowed to cool to 120 C. another 10 parts of ethylenediaminehydrate areadded, and the mixture is heated within 20 minutes to about 300 C. andkept at this temperature until a sample dissolves clearly in water,whereupon the heating is immediately interrupted.

In this manner there is obtained the2-heptadecenylimidazolinehydrochloride in the form of a semi-solidbrownish mass which dissolves clearly in water with the formation of astrongly foaming solution from which the base may be isolated in theusual manner.

Example 4 10 parts of oleic acid ethylester, 2 parts ofethylenediaminehydrate, 3 parts of ethylenediaminehydrochloride areheated together in the manner described in Example 1, save that thetemperature of the mass for the saponification of the ester is allowedto remain for some time (about 5-10 minutes) at 120130 C. The aqueoussolution of the heptadecenylimidazoline-hydrochloride is treated withsome active carbon and the free base is liberated by means of causticsoda; it is obtained in very good yield.

Example 5 8.5 parts of N-N-di-lauroylethylenediamide are heated with 3.3parts of ethylenediaminehydrochloride in an open flask, while stirring,in such a manner that after 5-10 minutes the mixture has a temperatureof about 2'l0-280 C. The heating is continued for another minutes to280-290 0., whereby the greater quantity of the hydrochloride passesinto solution. A sample then dissolves clearly in water.

Caustic soda solution precipitates from the aqueous solution theundecylimidazoline which is the product of reaction in approximatelyquantitative yield.

Example 6 10 parts of mono-lauroylethylenediamine-hydrochloride areheated for 5-10 minutes to 260-280 C. and then for a further 5-10minutes to 285295 C. The hydrochloride of the undecylimidazolineisthusformed. A similar result is obtained by substituting the correspondinghydrobromide or sulfate for themono-lauroylethylenediamine-hydrochloride or by using instead of themono-lauroylethylene-diamine-hydrochloride a derivative acylated withanother fatty acid of high molecular weight, such as for example themono-stearoyl-, the mono-oleoyl-, the monopalmitoy1-, the mono capryloylethylenedi amine-hydrochloride, or finally by using the corresponding1.2-propylenediamine or 2.3-- butylene-diamine derivatives.

Example 7 29 grams of a mixture of amides of such fatty acids as areobtained as first runnings by fractionating the products formed by theoxidation of paraffin are heated for about 1 hour at 120 C. to 130 C.and then gradually to 280 C. to 290 0. together with 9 grams of ethylenediamine and 15 grams of ethylenediamine hydrochloride. As soon as thereaction mass dissolves clearly in water the addition of heat isstopped. At about 150 C. the melt may readily be poured out of theflask.

The imidazoline thus obtained is a brown product which readily dissolvesin water, alcohol and aceton; the free base may be isolated from such asolution by means of alkalies.

Example 8 grams of ethylene diamine and grams of concentratedhydrochloric acid together with 270 grams of stearic acid amide areslowly heated to C. and then, after about 1 hour to 280 C. After thereaction mixture has been kept for a short time at this temperature itdissolves clearly in water. The aqueous solution foams strongly.

By means of alkalies the free imidazoline may readily be obtained fromthe light yellow heptadecyl-A2-imidazoline-hydrochloride thus formed.

We claim: 1

1. Process for the manufacture of 2-substituted midazolines whichcomprises reacting one mol )f a product selected from the groupconsisting 3f the fatty acid amides and naphthenio acid amides with halfa mol of a base which is substituted at two carbon atoms adjacent toeach other and linked by a single bond by an amino group each, of whichamino groups one contains two hydrogen atoms and the other at least onehydrogen atom, and with half a mol of a salt of such a base with astrong acid, the reaction being carried out at a high temperature.

2. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the fatty acid amides and naphthenic acid amides with halfa mol of a base which is substituted at two carbon atoms adjacent toeach other and linked by a single bond by an amino group each, of whichamino groups one contains two hydrogen atoms and the other at least onehydrogen atom, and with half a mol of a salt of such a base with astrong acid, the reaction being carried out at a high temperature whileusing an excess of the free base.

3. Process for the manufacture of 2-substitutedimidazolineswhichcomprises reacting one mol of a product selected fromthe group consisting of the fatty acid amides and naphthenic acid amideswith half a mol of a base which is substituted at two carbon atomsadjacent to each other and linked by a single bond by an amino groupeach, of which amino groups one contains two hydrogen atoms and theother at least one hydrogen atom, and with half a mol of a salt of sucha base with a strong acid, the reaction being carried out at a hightemperature while using an excess: of the salt of the base with a strongacid.

4. Process for the manufacture of 2-substituted imidazolineswhichcomprises reacting one mol of a product selected from the groupconsisting of the fatty acid amides and naphthenic acid amides with halfa mol of a base which is substituted at two carbon atoms adjacent toeach other and linked by a single bond by an amino group each, of whichamino groups one contains two hydrogen atoms and the other at least onehydrogen atom, and with half a mol of a salt of such a base with astrong acid, the reaction being carried out at a high temperature whileusing an excess of the free base and the salt of the base with a strongacid.

5. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the fatty acid'amides and naphthenic acid amides with halfa mol of a base which is substituted at two carbon atoms adjacent toeach other and linked by a single bond by an amino group each, of whichamino groups one contains two hydrogen atoms and the other at least onehydrogen atom, and with half a mol of a salt of such a base with astrong acid, the reaction being carried out at temperatures lyingbetween 200 C. and 300 C.

6-. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the amides of the fatty acids containing 10 to 13 carbonatoms with half a mol of a base which is substituted at two carbon atomsadjacent to each other and linked by a single bond by an amino groupeach, of which amino groups one contains two hydrogen atoms and theother at least one hydrogen atom, and with half a mol of a salt of sucha base with a strong acid, the reaction being otherwise carried out at ahigh temperature.

7. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the amides of the fatty acids containing 10 to 18 carbonatoms with half a mol of ethylene diamine and half a mol of a salt ofethylene diamine with a strong acid, the reaction being carried out attemperatures lying between 200 0. and 300 C.

8. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the amides of the fatty acids containing 10 to 18 carbonatoms with half a mol of ethylene diamine and half a mol of ethylenediamine hydrochloride, the reaction being carried out at temperatureslying between 200 C. and 300 C.

EDMUND WALDMANN. AUGUST CHWALA.

